Question:

Rolling mills exhibit what type of load torque characteristics?

A.

Constant torque characteristics

B.

Linearly rising torque characteristics

C.

Non-Linearly rising torque characteristics

D.

Non-Linearly decreasing torque characteristics

Answer» d. Non-Linearly decreasing torque characteristics

Question:

Type-A chopper is used for obtaining which type of mode?

A.

Motoring mode

B.

Regenerative braking mode

C.

Reverse motoring mode

D.

Reverse regenerative braking mode

Answer» a. Motoring mode

Question:

A motor of less than full load power rating can be used if the load is

A.

continuous duty

B.

short time duty

C.

intermittent periodic duty

D.

none of these.

Answer» b. short time duty

Question:

To save the energy during braking

A.

dynamic braking is used

B.

plugging is used

C.

regenerative braking is used

D.

mechanical braking is used.

Answer» c. regenerative braking is used

Question:

Rotor resistance speed control is used in

A.

squirrel cage induction motor

B.

synchronous motor

C.

slip ring induction motor

D.

dc shunt motor.

Answer» c. slip ring induction motor

Question:

Boost converter is used to _________

A.

Step down the voltage

B.

Step up the voltage

C.

Equalize the voltage

D.

Step up and step down the voltage

Answer» b. Step up the voltage

Question:

Most commonly used ac motor is

A.

Synchronous motor

B.

Slip ring induction motor

C.

Squirrel cage induction motor

D.

ac commutator induction motor.

Answer» c. Squirrel cage induction motor

Question:

Pole changing method of speed control is used in

A.

slip ring induction motor

B.

dc shunt motor

C.

dc series motor

D.

squirrel cage induction motor.

Answer» d. squirrel cage induction motor.

Question:

To get speed higher than the base speed of the dc shunt motor

A.

armature resistance control is used

B.

field resistance control is used

C.

armature voltage control is used

D.

none of these.

Answer» b. field resistance control is used